Mashable has a review of a new Twitter desktop application Seesmic Desktop: A Threat to TweetDeck? It sounds promising but also very similar to TweetDeck (which I use).
I agree with this conclusion by Mashable:
In the never ending battle for your desktop, the real winner isn’t Seesmic or TweetDeck, but rather you, the end user.
TechCrunch posted that Seesmic Unveils A Formidable New Twitter Client To Rival Tweetdeck: Seesmic Desktop.
TweetDeck – Twitter on your desktop